Merge 4058-4065: Add a stack backtrace to the panic message.

Note that to use this for full effect, varnishd should be installed
unstripped.

r4058:
Also remember compat execinfo.h file.

r4059:
Tell autocrap about compat/execinfo.h

r4060:
Attempt to add a stack backtrace to the panic message.

r4061:
Spit out more information on panic

r4062:
Autocrap the dladdr() functions existence.

r4063:
More autocrappery.

r4064:
Comment out unneeded function.

r4065:
Pass a void* to Symbol_Lookup() to avoid stdint requirement on
common.h



git-svn-id: http://www.varnish-cache.org/svn/branches/2.0@4256 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_panic.c

@@ -37,6 +37,11 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#ifndef HAVE_EXECINFO_H
+#include "compat/execinfo.h"
+#else
+#include <execinfo.h>
+#endif
 #include "cache.h"
 #include "cache_backend.h"
 #include "vcl.h"
@@ -131,21 +136,21 @@ pan_storage(const struct storage *st)
 /*--------------------------------------------------------------------*/
 
 static void
-pan_http(const struct http *h)
+pan_http(const char *id, const struct http *h, int indent)
 {
 	int i;
 
-	vsb_printf(vsp, "    http = {\n");
-	pan_ws(h->ws, 6);
-	if (h->nhd > HTTP_HDR_FIRST) {
-		vsb_printf(vsp, "      hd = {\n");
-		for (i = HTTP_HDR_FIRST; i < h->nhd; ++i)
-			vsb_printf(vsp, "        \"%.*s\",\n",
-			    (int)(h->hd[i].e - h->hd[i].b),
-			    h->hd[i].b);
-		vsb_printf(vsp, "      },\n");
+	vsb_printf(vsp, "%*shttp[%s] = {\n", indent, "", id);
+	vsb_printf(vsp, "%*sws = %p[%s]\n", indent + 2, "",
+	    h->ws, h->ws ? h->ws->id : "");
+	for (i = 0; i < h->nhd; ++i) {
+		if (h->hd[i].b == NULL && h->hd[i].e == NULL)
+			continue;
+		vsb_printf(vsp, "%*s\"%.*s\",\n", indent + 4, "",
+		    (int)(h->hd[i].e - h->hd[i].b),
+		    h->hd[i].b);
 	}
-	vsb_printf(vsp, "    },\n");
+	vsb_printf(vsp, "%*s},\n", indent, "");
 }
 
 
@@ -159,7 +164,7 @@ pan_object(const struct object *o)
 	vsb_printf(vsp, "  obj = %p {\n", o);
 	vsb_printf(vsp, "    refcnt = %u, xid = %u,\n", o->refcnt, o->xid);
 	pan_ws(o->ws_o, 4);
-	pan_http(o->http);
+	pan_http("obj", o->http, 4);
 	vsb_printf(vsp, "    len = %u,\n", o->len);
 	vsb_printf(vsp, "    store = {\n");
 	VTAILQ_FOREACH(st, &o->store, list)
@@ -190,8 +195,7 @@ static void
 pan_wrk(const struct worker *wrk)
 {
 
-	vsb_printf(vsp, "    worker = %p {\n", wrk);
-	vsb_printf(vsp, "    },\n");
+	vsb_printf(vsp, "  worker = %p\n", wrk);
 }
 
 /*--------------------------------------------------------------------*/
@@ -229,7 +233,11 @@ pan_sess(const struct sess *sp)
 		    "  err_code = %d, err_reason = %s,\n", sp->err_code,
 		    sp->err_reason ? sp->err_reason : "(null)");
 
+	vsb_printf(vsp, "  restarts = %d, esis = %d\n",
+	    sp->restarts, sp->esis);
+
 	pan_ws(sp->ws, 2);
+	pan_http("req", sp->http, 2);
 
 	if (sp->wrk != NULL)
 		pan_wrk(sp->wrk);
@@ -248,6 +256,28 @@ pan_sess(const struct sess *sp)
 
 /*--------------------------------------------------------------------*/
 
+static void
+pan_backtrace(void)
+{
+	void *array[10];
+	size_t size;
+	size_t i;
+
+	size = backtrace (array, 10);
+	vsb_printf(vsp, "Backtrace:\n");
+	for (i = 0; i < size; i++) {
+		vsb_printf (vsp, "  ");
+		if (Symbol_Lookup(vsp, array[i]) < 0) {
+			char **strings;
+			strings = backtrace_symbols(&array[i], 1);
+			vsb_printf(vsp, "%p: %s", array[i], strings[0]);
+		}
+		vsb_printf (vsp, "\n");
+	}
+}
+
+/*--------------------------------------------------------------------*/
+
 static void
 pan_ic(const char *func, const char *file, int line, const char *cond,
     int err, int xxx)
@@ -264,7 +294,7 @@ pan_ic(const char *func, const char *file, int line, const char *cond,
 		break;
 	case 2:
 		vsb_printf(vsp,
-		    "Panic from VCL:\n%s\n", cond);
+		    "Panic from VCL:\n  %s\n", cond);
 		break;
 	case 1:
 		vsb_printf(vsp,
@@ -276,16 +306,19 @@ pan_ic(const char *func, const char *file, int line, const char *cond,
 	case 0:
 		vsb_printf(vsp,
 		    "Assert error in %s(), %s line %d:\n"
-		    "  Condition(%s) not true.",
+		    "  Condition(%s) not true.\n",
 		    func, file, line, cond);
 		break;
 	}
 	if (err)
-		vsb_printf(vsp, "  errno = %d (%s)", err, strerror(err));
+		vsb_printf(vsp, "errno = %d (%s)\n", err, strerror(err));
 
 	q = THR_GetName();
 	if (q != NULL)
-		vsb_printf(vsp, "  thread = (%s)", q);
+		vsb_printf(vsp, "thread = (%s)\n", q);
+
+	pan_backtrace();
+
 	if (!(params->diag_bitmap & 0x2000)) {
 		sp = THR_GetSession();
 		if (sp != NULL)

bin/varnishd/common.h

@@ -42,6 +42,10 @@ void VSL_Panic(int *len, char **ptr);
 void VSL_MgtInit(const char *fn, unsigned size);
 extern struct varnish_stats *VSL_stats;
 
+/* varnishd.c */
+struct vsb;
+int Symbol_Lookup(struct vsb *vsb, void *ptr);
+
 #define TRUST_ME(ptr)	((void*)(uintptr_t)(ptr))
 
 /* Really belongs in mgt.h, but storage_file chokes on both */

bin/varnishd/varnishd.c

@@ -414,6 +414,92 @@ cli_check(const struct cli *cli)
 	exit (2);
 }
 
+/*--------------------------------------------------------------------
+ * All praise POSIX!  Thanks to our glorious standards there are no
+ * standard way to get a back-trace of the stack, and even if we hack
+ * that together from spit and pieces of string, there is no way no
+ * standard way to translate a pointer to a symbol, which returns anything
+ * usable.  (See for instance FreeBSD PR-134391).
+ *
+ * Attempt to run nm(1) on our binary during startup, hoping it will
+ * give us a usable list of symbols.
+ */
+
+struct symbols {
+	uintptr_t		a;
+	char			*n;
+	VTAILQ_ENTRY(symbols)	list;
+};
+
+static VTAILQ_HEAD(,symbols) symbols = VTAILQ_HEAD_INITIALIZER(symbols);
+
+int
+Symbol_Lookup(struct vsb *vsb, void *ptr)
+{
+	struct symbols *s, *s0;
+	uintptr_t pp;
+
+	pp = (uintptr_t)ptr;
+	s0 = NULL;
+	VTAILQ_FOREACH(s, &symbols, list) {
+		if (s->a > pp)
+			continue;
+		if (s0 != NULL && s->a < s0->a)
+			continue;
+		s0 = s;
+	}
+	if (s0 == NULL)
+		return (-1);
+	vsb_printf(vsb, "%p", ptr);
+	if (s0 != NULL)
+		vsb_printf(vsb, ": %s+%jx", s0->n, (uintmax_t)pp - s0->a);
+	return (0);
+}
+
+static void
+Symbol_hack(const char *a0)
+{
+	char buf[BUFSIZ], *p, *e;
+	FILE *fi;
+	uintptr_t a;
+	struct symbols *s;
+
+	strcpy(buf, "nm -an ");
+	strcat(buf, a0);
+	fi = popen(buf, "r");
+	if (fi != NULL) {
+		while (fgets(buf, sizeof buf, fi)) {
+			if (buf[0] == ' ')
+				continue;
+			p = NULL;
+			a = strtoul(buf, &p, 16);
+			if (p == NULL)
+				continue;
+			if (a == 0)
+				continue;
+			if (*p++ != ' ')
+				continue;
+			p++;
+			if (*p++ != ' ')
+				continue;
+			if (*p <= ' ')
+				continue;
+			e = strchr(p, '\0');
+			AN(e);
+			while (e > p && isspace(e[-1]))
+				e--;
+			*e = '\0';
+			s = malloc(sizeof *s + strlen(p) + 1);
+			AN(s);
+			s->a = a;
+			s->n = (void*)(s + 1);
+			strcpy(s->n, p);
+			VTAILQ_INSERT_TAIL(&symbols, s, list);
+		}
+		pclose(fi);
+	}
+}
+
 /*--------------------------------------------------------------------*/
 
 int
@@ -443,6 +529,11 @@ main(int argc, char * const *argv)
 	setbuf(stdout, NULL);
 	setbuf(stderr, NULL);
 
+	Symbol_hack(argv[0]);
+
+	/* for ASSERT_MGT() */
+	mgt_pid = getpid();
+
 	/*
 	 * Run in UTC timezone, on the off-chance that this operating
 	 * system does not have a timegm() function, and translates

configure.ac

@@ -103,6 +103,7 @@ AC_TYPE_SIZE_T
 AC_FUNC_VPRINTF
 AC_CHECK_FUNCS([strerror])
 AC_FUNC_STRERROR_R
+AC_CHECK_FUNCS([dladdr])
 AC_CHECK_FUNCS([socket])
 AC_CHECK_FUNCS([strptime])
 AC_CHECK_FUNCS([fmtcheck])

include/Makefile.am

@@ -14,6 +14,7 @@ nobase_noinst_HEADERS = \
 	cli_priv.h \
 	compat/asprintf.h \
 	compat/daemon.h \
+	compat/execinfo.h \
 	compat/setproctitle.h \
 	compat/srandomdev.h \
 	compat/strlcat.h \

include/compat/execinfo.h

+/*
+ * Copyright (c) 2003 Maxim Sobolev <sobomax@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Id: execinfo.h,v 1.2 2004/07/19 05:20:29 sobomax Exp $
+ */
+
+#ifndef COMPAT_EXECINFO_H_INCLUDED
+#define COMPAT_EXECINFO_H_INCLUDED
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int     backtrace(void **, int);
+char ** backtrace_symbols(void *const *, int);
+void    backtrace_symbols_fd(void *const *, int, int);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* COMPAT_EXECINFO_H_INCLUDED */